export const humanize = {};

humanize.pad = function(str, count, padChar, type) {
  str += '';
  if (!padChar) {
    padChar = ' ';
  } else if (padChar.length > 1) {
    padChar = padChar.charAt(0);
  }
  type = (type === undefined) ? 'left' : 'right';

  if (type === 'right') {
    while (str.length < count) {
      str = str + padChar;
    }
  } else {
    // default to left
    while (str.length < count) {
      str = padChar + str;
    }
  }

  return str;
};

// gets current unix time
humanize.time = function() {
  return new Date().getTime() / 1000;
};

/**
 * PHP-inspired date
 */

/*  jan  feb  mar  apr  may  jun  jul  aug  sep  oct  nov  dec */
var dayTableCommon = [0, 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];
var dayTableLeap = [0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335];
// var mtable_common[13] = {  0,  31,  28,  31,  30,  31,  30,  31,  31,  30,  31,  30,  31 };
// static int ml_table_leap[13]   = {  0,  31,  29,  31,  30,  31,  30,  31,  31,  30,  31,  30,  31 };


humanize.date = function(format, timestamp) {
  var jsdate = ((timestamp === undefined) ? new Date() : // Not provided
    (timestamp instanceof Date) ? new Date(timestamp) : // JS Date()
    new Date(timestamp * 1000) // UNIX timestamp (auto-convert to int)
  );

  var formatChr = /\\?([a-z])/gi;
  var formatChrCb = function(t, s) {
    return f[t] ? f[t]() : s;
  };

  var shortDayTxt = ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'];
  var monthTxt = ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October',
    'November', 'December'
  ];

  var f = {
    /* Day */
    // Day of month w/leading 0; 01..31
    d: function() { return humanize.pad(f.j(), 2, '0'); },

    // Shorthand day name; Mon..Sun
    D: function() { return f.l().slice(0, 3); },

    // Day of month; 1..31
    j: function() { return jsdate.getDate(); },

    // Full day name; Monday..Sunday
    l: function() { return shortDayTxt[f.w()]; },

    // ISO-8601 day of week; 1[Mon]..7[Sun]
    N: function() { return f.w() || 7; },

    // Ordinal suffix for day of month; st, nd, rd, th
    S: function() {
      var j = f.j();
      return j > 4 && j < 21 ? 'th' : { 1: 'st', 2: 'nd', 3: 'rd' } [j % 10] || 'th';
    },

    // Day of week; 0[Sun]..6[Sat]
    w: function() { return jsdate.getDay(); },

    // Day of year; 0..365
    z: function() {
      return (f.L() ? dayTableLeap[f.n()] : dayTableCommon[f.n()]) + f.j() - 1;
    },

    /* Week */
    // ISO-8601 week number
    W: function() {
      // days between midweek of this week and jan 4
      // (f.z() - f.N() + 1 + 3.5) - 3
      var midWeekDaysFromJan4 = f.z() - f.N() + 1.5;
      // 1 + number of weeks + rounded week
      return humanize.pad(1 + Math.floor(Math.abs(midWeekDaysFromJan4) / 7) + (midWeekDaysFromJan4 % 7 > 3.5 ? 1 :
        0), 2, '0');
    },

    /* Month */
    // Full month name; January..December
    F: function() { return monthTxt[jsdate.getMonth()]; },

    // Month w/leading 0; 01..12
    m: function() { return humanize.pad(f.n(), 2, '0'); },

    // Shorthand month name; Jan..Dec
    M: function() { return f.F().slice(0, 3); },

    // Month; 1..12
    n: function() { return jsdate.getMonth() + 1; },

    // Days in month; 28..31
    t: function() { return (new Date(f.Y(), f.n(), 0)).getDate(); },

    /* Year */
    // Is leap year?; 0 or 1
    L: function() { return new Date(f.Y(), 1, 29).getMonth() === 1 ? 1 : 0; },

    // ISO-8601 year
    o: function() {
      var n = f.n();
      var W = f.W();
      return f.Y() + (n === 12 && W < 9 ? -1 : n === 1 && W > 9);
    },

    // Full year; e.g. 1980..2010
    Y: function() { return jsdate.getFullYear(); },

    // Last two digits of year; 00..99
    y: function() { return (String(f.Y())).slice(-2); },

    /* Time */
    // am or pm
    a: function() { return jsdate.getHours() > 11 ? 'pm' : 'am'; },

    // AM or PM
    A: function() { return f.a().toUpperCase(); },

    // Swatch Internet time; 000..999
    B: function() {
      var unixTime = jsdate.getTime() / 1000;
      var secondsPassedToday = unixTime % 86400 + 3600; // since it's based off of UTC+1
      if (secondsPassedToday < 0) { secondsPassedToday += 86400; }
      var beats = ((secondsPassedToday) / 86.4) % 1000;
      if (unixTime < 0) {
        return Math.ceil(beats);
      }
      return Math.floor(beats);
    },

    // 12-Hours; 1..12
    g: function() { return f.G() % 12 || 12; },

    // 24-Hours; 0..23
    G: function() { return jsdate.getHours(); },

    // 12-Hours w/leading 0; 01..12
    h: function() { return humanize.pad(f.g(), 2, '0'); },

    // 24-Hours w/leading 0; 00..23
    H: function() { return humanize.pad(f.G(), 2, '0'); },

    // Minutes w/leading 0; 00..59
    i: function() { return humanize.pad(jsdate.getMinutes(), 2, '0'); },

    // Seconds w/leading 0; 00..59
    s: function() { return humanize.pad(jsdate.getSeconds(), 2, '0'); },

    // Microseconds; 000000-999000
    u: function() { return humanize.pad(jsdate.getMilliseconds() * 1000, 6, '0'); },

    // Whether or not the date is in daylight savings time
    /*
    I: function () {
      // Compares Jan 1 minus Jan 1 UTC to Jul 1 minus Jul 1 UTC.
      // If they are not equal, then DST is observed.
      var Y = f.Y();
      return 0 + ((new Date(Y, 0) - Date.UTC(Y, 0)) !== (new Date(Y, 6) - Date.UTC(Y, 6)));
    },
    */

    // Difference to GMT in hour format; e.g. +0200
    O: function() {
      var tzo = jsdate.getTimezoneOffset();
      var tzoNum = Math.abs(tzo);
      return (tzo > 0 ? '-' : '+') + humanize.pad(Math.floor(tzoNum / 60) * 100 + tzoNum % 60, 4, '0');
    },

    // Difference to GMT w/colon; e.g. +02:00
    P: function() {
      var O = f.O();
      return (O.substr(0, 3) + ':' + O.substr(3, 2));
    },

    // Timezone offset in seconds (-43200..50400)
    Z: function() { return -jsdate.getTimezoneOffset() * 60; },

    // Full Date/Time, ISO-8601 date
    c: function() { return 'Y-m-d\\TH:i:sP'.replace(formatChr, formatChrCb); },

    // RFC 2822
    r: function() { return 'D, d M Y H:i:s O'.replace(formatChr, formatChrCb); },

    // Seconds since UNIX epoch
    U: function() { return jsdate.getTime() / 1000 || 0; }
  };

  return format.replace(formatChr, formatChrCb);
};


/**
 * format number by adding thousands separaters and significant digits while rounding
 */
humanize.numberFormat = function(number, decimals, decPoint, thousandsSep) {
  decimals = isNaN(decimals) ? 2 : Math.abs(decimals);
  decPoint = (decPoint === undefined) ? '.' : decPoint;
  thousandsSep = (thousandsSep === undefined) ? ',' : thousandsSep;

  var sign = number < 0 ? '-' : '';
  number = Math.abs(+number || 0);

  var intPart = parseInt(number.toFixed(decimals), 10) + '';
  var j = intPart.length > 3 ? intPart.length % 3 : 0;

  return sign + (j ? intPart.substr(0, j) + thousandsSep : '') + intPart.substr(j).replace(/(\d{3})(?=\d)/g, '$1' +
    thousandsSep) + (decimals ? decPoint + Math.abs(number - intPart).toFixed(decimals).slice(2) : '');
};


/**
 * For dates that are the current day or within one day, return 'today', 'tomorrow' or 'yesterday', as appropriate.
 * Otherwise, format the date using the passed in format string.
 *
 * Examples (when 'today' is 17 Feb 2007):
 * 16 Feb 2007 becomes yesterday.
 * 17 Feb 2007 becomes today.
 * 18 Feb 2007 becomes tomorrow.
 * Any other day is formatted according to given argument or the DATE_FORMAT setting if no argument is given.
 */
humanize.naturalDay = function(timestamp, format) {
  timestamp = (timestamp === undefined) ? humanize.time() : timestamp;
  format = (format === undefined) ? 'Y-m-d' : format;

  var oneDay = 86400;
  var d = new Date();
  var today = (new Date(d.getFullYear(), d.getMonth(), d.getDate())).getTime() / 1000;

  if (timestamp < today && timestamp >= today - oneDay) {
    return 'yesterday';
  } else if (timestamp >= today && timestamp < today + oneDay) {
    return 'today';
  } else if (timestamp >= today + oneDay && timestamp < today + 2 * oneDay) {
    return 'tomorrow';
  }

  return humanize.date(format, timestamp);
};

/**
 * returns a string representing how many seconds, minutes or hours ago it was or will be in the future
 * Will always return a relative time, most granular of seconds to least granular of years. See unit tests for more details
 */
humanize.relativeTime = function(timestamp) {
  timestamp = (timestamp === undefined) ? humanize.time() : timestamp;

  var currTime = humanize.time();
  var timeDiff = currTime - timestamp;

  // within 2 seconds
  if (timeDiff < 2 && timeDiff > -2) {
    return (timeDiff >= 0 ? 'just ' : '') + 'now';
  }

  // within a minute
  if (timeDiff < 60 && timeDiff > -60) {
    return (timeDiff >= 0 ? Math.floor(timeDiff) + ' seconds ago' : 'in ' + Math.floor(-timeDiff) + ' seconds');
  }

  // within 2 minutes
  if (timeDiff < 120 && timeDiff > -120) {
    return (timeDiff >= 0 ? 'about a minute ago' : 'in about a minute');
  }

  // within an hour
  if (timeDiff < 3600 && timeDiff > -3600) {
    return (timeDiff >= 0 ? Math.floor(timeDiff / 60) + ' minutes ago' : 'in ' + Math.floor(-timeDiff / 60) +
      ' minutes');
  }

  // within 2 hours
  if (timeDiff < 7200 && timeDiff > -7200) {
    return (timeDiff >= 0 ? 'about an hour ago' : 'in about an hour');
  }

  // within 24 hours
  if (timeDiff < 86400 && timeDiff > -86400) {
    return (timeDiff >= 0 ? Math.floor(timeDiff / 3600) + ' hours ago' : 'in ' + Math.floor(-timeDiff / 3600) +
      ' hours');
  }

  // within 2 days
  var days2 = 2 * 86400;
  if (timeDiff < days2 && timeDiff > -days2) {
    return (timeDiff >= 0 ? '1 day ago' : 'in 1 day');
  }

  // within 29 days
  var days29 = 29 * 86400;
  if (timeDiff < days29 && timeDiff > -days29) {
    return (timeDiff >= 0 ? Math.floor(timeDiff / 86400) + ' days ago' : 'in ' + Math.floor(-timeDiff / 86400) +
      ' days');
  }

  // within 60 days
  var days60 = 60 * 86400;
  if (timeDiff < days60 && timeDiff > -days60) {
    return (timeDiff >= 0 ? 'about a month ago' : 'in about a month');
  }

  var currTimeYears = parseInt(humanize.date('Y', currTime), 10);
  var timestampYears = parseInt(humanize.date('Y', timestamp), 10);
  var currTimeMonths = currTimeYears * 12 + parseInt(humanize.date('n', currTime), 10);
  var timestampMonths = timestampYears * 12 + parseInt(humanize.date('n', timestamp), 10);

  // within a year
  var monthDiff = currTimeMonths - timestampMonths;
  if (monthDiff < 12 && monthDiff > -12) {
    return (monthDiff >= 0 ? monthDiff + ' months ago' : 'in ' + (-monthDiff) + ' months');
  }

  var yearDiff = currTimeYears - timestampYears;
  if (yearDiff < 2 && yearDiff > -2) {
    return (yearDiff >= 0 ? 'a year ago' : 'in a year');
  }

  return (yearDiff >= 0 ? yearDiff + ' years ago' : 'in ' + (-yearDiff) + ' years');
};

/**
 * Converts an integer to its ordinal as a string.
 *
 * 1 becomes 1st
 * 2 becomes 2nd
 * 3 becomes 3rd etc
 */
humanize.ordinal = function(number) {
  number = parseInt(number, 10);
  number = isNaN(number) ? 0 : number;
  var sign = number < 0 ? '-' : '';
  number = Math.abs(number);
  var tens = number % 100;

  return sign + number + (tens > 4 && tens < 21 ? 'th' : { 1: 'st', 2: 'nd', 3: 'rd' } [number % 10] || 'th');
};

/**
 * Formats the value like a 'human-readable' file size (i.e. '13 KB', '4.1 MB', '102 bytes', etc).
 *
 * For example:
 * If value is 123456789, the output would be 117.7 MB.
 */
humanize.filesize = function(filesize, kilo, decimals, decPoint, thousandsSep, suffixSep) {
  kilo = (kilo === undefined) ? 1024 : kilo;
  if (filesize <= 0) { return '0 bytes'; }
  if (filesize < kilo && decimals === undefined) { decimals = 0; }
  if (suffixSep === undefined) { suffixSep = ' '; }
  return humanize.intword(filesize, ['bytes', 'KB', 'MB', 'GB', 'TB', 'PB'], kilo, decimals, decPoint, thousandsSep,
    suffixSep);
};

/**
 * Formats the value like a 'human-readable' number (i.e. '13 K', '4.1 M', '102', etc).
 *
 * For example:
 * If value is 123456789, the output would be 117.7 M.
 */
humanize.intword = function(number, units, kilo, decimals, decPoint, thousandsSep, suffixSep) {
  var humanized, unit;

  units = units || ['', 'K', 'M', 'B', 'T'],
    unit = units.length - 1,
    kilo = kilo || 1000,
    decimals = isNaN(decimals) ? 2 : Math.abs(decimals),
    decPoint = decPoint || '.',
    thousandsSep = thousandsSep || ',',
    suffixSep = suffixSep || '';

  for (var i = 0; i < units.length; i++) {
    if (number < Math.pow(kilo, i + 1)) {
      unit = i;
      break;
    }
  }
  humanized = number / Math.pow(kilo, unit);

  var suffix = units[unit] ? suffixSep + units[unit] : '';
  return humanize.numberFormat(humanized, decimals, decPoint, thousandsSep) + suffix;
};

/**
 * Replaces line breaks in plain text with appropriate HTML
 * A single newline becomes an HTML line break (<br />) and a new line followed by a blank line becomes a paragraph break (</p>).
 * 
 * For example:
 * If value is Joel\nis a\n\nslug, the output will be <p>Joel<br />is a</p><p>slug</p>
 */
humanize.linebreaks = function(str) {
  // remove beginning and ending newlines
  str = str.replace(/^([\n|\r]*)/, '');
  str = str.replace(/([\n|\r]*)$/, '');

  // normalize all to \n
  str = str.replace(/(\r\n|\n|\r)/g, "\n");

  // any consecutive new lines more than 2 gets turned into p tags
  str = str.replace(/(\n{2,})/g, '</p><p>');

  // any that are singletons get turned into br
  str = str.replace(/\n/g, '<br />');
  return '<p>' + str + '</p>';
};

/**
 * Converts all newlines in a piece of plain text to HTML line breaks (<br />).
 */
humanize.nl2br = function(str) {
  return str.replace(/(\r\n|\n|\r)/g, '<br />');
};

/**
 * Truncates a string if it is longer than the specified number of characters.
 * Truncated strings will end with a translatable ellipsis sequence ('…').
 */
humanize.truncatechars = function(string, length) {
  if (string.length <= length) { return string; }
  return string.substr(0, length) + '…';
};

/**
 * Truncates a string after a certain number of words.
 * Newlines within the string will be removed.
 */
humanize.truncatewords = function(string, numWords) {
  var words = string.split(' ');
  if (words.length < numWords) { return string; }
  return words.slice(0, numWords).join(' ') + '…';
};